Estratificação, ambientes e giberelina na antecipação da enxertia do pessegueiro ‘Okinawa’

Abstract

This study was carried out in the Orchard of the Federal University of Lavras (UFLA) to verify the possibility of anticipation of the grafting point of rootstocks of peach tree ‘Okinawa’, when submitted to different stone- stratification periods (0, 30, 60 and 90 days) in refrigerator 5oC, absence and presence of gibberellin (500 mg L-1 of GA3/24h) and in three environmental conditions (greenhouse, mesh and open sky). After each stratification period, the stones were broken to remove the nuts, which were sown in foam trays and afterwards transplanted to plastic bags, which were maintained in the three environmental conditions. The experimental design was completely randomized factorial 4x2x3, four replicates and 14 nuts per plot. Characteristics evaluated: percentage of total emergence of the seeds, interval between the first and last emergence of seeds, average time to reach transplanting and grafting point. Follows that stones of peach tree ‘Okinawa’ need a minimum period of 60 day of stratification in damp cold for physiological dormancy of seeds to be overcome; the shortest emergency interval of seeds was obtained at 60 days of stratification and in the greenhouse and by increasing stratification period for 90 days, one manages to decrease the time for plants to reach transplanting point and ideal point for grafting.The use of Gibberellin to overcome dormancy of Okinawa 'peach has not replaced the stratification, not interfering in anticipation of the ideal point of grafting of rootstocks.